Polarity switch



Feb. 19, 1963 L. F. PETTIT, JR., ETAL 3,078,354

POLARITY SWITCH Filed Jan. 20, 1960 2 Sheets-Sheet 1 WITNESSES Fig. 2 INVENTORS (4 5 Lewis F. Pettit,Jn 8 y K Joseph F. Miller ATTORNEY Feb. 19, 1963 F. PETTIT, JR., ETAL 3,073,354

FOLARITY SWITCH Filed Jan. 20', 1960 2 Sheets-81199122 24 24' 27 25 /l6' 5 Fig. 5

6 7 Load 34 3,073,354 PGLARHTY SWITCH Lewis F. Pettit, Jr., and Joseph F. Miller, Ciarence, N.Y., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsyivania Filed Jan. 20, 1960, Ser. No. 3,554 6 Claims. (Cl. 200-6) This invention relates to reversing switches and more particularly to very heavy duty reversing switches as needed for example in the electric welding art.

In the arc welding art the switches needed are subject to very severe working conditions and have to be able to carry electric currents from 200 to 500 amperes. The rating has to be for continuous use with heavy currents.

It is thus a very desirable feature to use switches that give reliable performance over long periods of time even though the switch units carry heavy currents.

Some of the broad objects of this invention are the provision of a switch of a simple, reliable, and rugged construction, and that will have an improved current carrying capacity.

Other broad objects of this invention are the provision of a switch having the very minimum number of simple, interchangeable, and readily replaceable parts so as to reduce the cost of manufacture of the parts to a minimum and to facilitate assembly of the switch.

The objects hereinbefore stated are merely illustrative. Other objects and advantages of this invention will be come more apparent from a study of the following specification when done with respect to the drawings, in which:

FIGURE 1 is a plan view of a reversing switch em bodying the invention;

FIG. 2 is a view from the front side of the showing in FIG. 1;

FIG. 3 is a sectional view on section line IIIIH of FIG. 2;

FIG. 4 is a sectional View of a detail taken on section line lV-IV of FIG. 2;

FIG. 5 is a sectional view of another detail taken on section line V-V of FIG. 2; and,

FIG. 6 is a diagrammatic showing of the switch and circuitry it controls.

Referring to the drawings, the switch panel, or base 1 is a generally rectangularly shaped structure of insulating material, and has parallel front and rear side-walls. The switch panel is provided along its front bottom edge in the front side wall with a groove 19. The face of the front side wall is provided with a pair of shallow grooves 20 and 21 radially disposed with respect to an axis disposed normal to the side walls and a selected distance above the bottom of the panel 1. The angle between the longitudinal directions of the grooves is 90 and the angles between the longitudinal directions and the bottom of the panel are in each case 45. The read side-wall is identical in configuration to the front side-wall and is provided with a groove 19 at the bottom edge, and with the shallow grooves 20 and 21'. The grooves 19', 20' and 2-1 are, respectively, parallel to grooves 19, 20 and 21.

A cylindrical opening 22 is disposed about the axis 23 and receives the switch disc 2 of insulating material and consisting of a front part 24 and a like, or identically shaped rear part 24'. Each part is provided with a pair of like inwardly projecting sections of a cylinder to snugly rotatably fit into the cylindrical opening 22. The flat surfaces of the section plane of the sections facing each other are disposed in parallel relation to each other and between them receive two heavy copper straps 4 and 4' held against longitudinal slippage n the switch disc 2 springs and 5, substantially the width of the straps ECQ 4 and 4' but somewhat shorter are also received on the studs 25 and 25', respectively, and in their action firmly bias the straps 4 and 4' inwardly.

A strap 27 carrying a shaft 3 to which a suitable actuating handle may be attached is rigidly bolted to the switch disc by the bolts 17 respectively provided with suitable washers and nuts.

The bottom grooves 19 and 19' receive the heavy copper straps 18 and 18'. The strap 18 at the right is provided with a heavy front copper connecter F9 that is held firmly in electrical contact with strap 18 by the nut and bolt assembly 11 and insulating sleeves 13 shown in detail in FIG. 5.

The heavy copper strap 18' is similarly provided at its rear left end with a heavy rear copper connector R9, similarly held by a nut and bolt assembly and insulating sleeves not shown in detail.

Grooves 20 and 21, receive the heavy copper L-shaped like Straps 6 and 16. The short legs 10 and 12 of these straps project forwardly. The grooves 20 and 21' receive the identically shaped heavy copper L-shaped straps 6' and 16'. The short legs 10' and 12 of these straps project rearwardly. A heavy copper jumper connection 7 connects leg 1t) to leg 12' and a somewhat similar jumper connection 8, bowed upwardly so as not to contact the jumper connection 7, is connected from leg 10' to leg 12. A source of direct current is, in use of this switch, connected to legs 10 and 1t), and a suitable load that is to be controlled, is connected across connectors P9 and R9.

From the foregoing it will be noted that the straps 4 and 4', regardless of Whether in the counterclockwise position against left stop LS, in the vertical position shown in FIG. 2 or in the clockwise position against the right stop RS, are always in firm electrical engagement with the straps 18 and 18, respectively. When the shaft 3 is turned counterclockwise so that strap 4 engages stop LS then straps 4 and 4' engage the connectors, or straps, 6 and 6'. If the legs 10 and 10' are connected to a source of direct current energy, as a positive potential on leg 10 and a negative potential on leg 10, then, with respect to terminals 32 and 31, an energizing circuit is established from positive terminal 32, leg 10 and connector 6, movable strap 4, strap 18, front connector F9, conductor 33, load 34 in one direction, conductor 35, rear connector R9, strap movable strap 4', strap 6', to the negative supply lead 31.

When the movable straps 4 and 4 are moved clockwise a circuit is established from conductor 32, leg 10 of strap 6, jumper connection 7, leg 12 of strap 16', movable strap 4., strap 13', rear connector R9, conductor 35, load 34 in a reverse direction, conductor 33, front connector F9, straps 18 and 4, strap 16, leg 12, jumper connection 8, leg 10' and strap 6, to the negative lead 31.

It will be noted that parts 24 and 24 of the contact disc 2 are identical in shape and thus interchangeable. Parts 1 and 2 are of molded material to ensure the utmost in reliability. It will also be noted that parts F9 and R9 are identical in shape, parts 18 and 18' are identical in shape, and parts 6, 6', 16, and 16' are all identical in construction. The nut and bolt assemblies are also identical.

It is thus apparent that a rugged switch of the simplest construction is provided that is easy to manufacture and maintain, and damaged parts can be replaced in the field.

While but one embodiment has been disclosed, the invention is, however, not limited to the one embodiment, but that modifications may be made all within the spirit of this invention.

We claim as our invention:

1. In a heavy duty reversing switch, in combination, a base of insulating material having a front side-Wall and spreess a parallelly disposed rear side-wall, a first group of three relatively heavy strap-like metal conductors mounted on the front side-wall, two of said conductors being disposed at a selected angle with respect to each other and radially with respect to a pivot axis normal to the side-walls and having their inner ends spaced from the pivot axis, the third conductor being disposed to one side of the pivot axis and angularly spaced from said two conductors, a similar second group of three conductors mounted similarly on the rear side-wall with corresponding conductors of the two groups being disposed in parallel relation to each other, connectors connected to the third conductor of each group across which a load to be controlled may be connected, a pair of strap-like relatively heavy metal conductors pivotally mounted at said pivot axis and disposed in parallel relation to each other with the front pivotal conductor being disposed to sweep the front sidewall and the rear pivotal conductor being disposed to sweep the rear side-wall, whereby the front pivotal conductor may be selectively moved to connect either the first radial conductor of the front group to the third of the front group or the second radial conductor of the front group to the third of the front group, or neither the first nor second of the front group to the third of the front group while at the same time the rear pivotal conductor during pivotal movement selectively makes contact with corresponding conductors of the rear group of three conductors, a firstjumper connection from the left front radial conductor to the right rear radial conductor, a second jumper connection from the left rear radial conductor to the front right radial conductor, and connector means whereby a suitable source of electric energy may be connected across said left front radial conductor and rear left radial conductor, whereby movement of said pivotal conductors from a selected counterclockwise position to a selected clockwise position will effect reside-walls, a first group of three conductors mounted in the front side-wall, the first and second of this group being angularly spaced and radially disposed with respect to a pivot axis normal to the side-walls and their inner ends spaced from the pivot axis, and the third being disposed to one side of the pivot axis and angularly spaced from the first and second conductors, a similar second group of three conductors in the rear side-wall with corresponding conductors of the two groups being disposed in parallel relation, a pair of parallelly spaced conductors pivotally mounted on the pivot axis with the front pivotal conductor sweeping the front side-wall and the rear pivotal conductor the rear side-wall to thus selectively interconnect the front radial conductors with the front third and the rear radial conductors with the rear third, means for connecting the front left radial conductor to the right rear radial conductor, and means for connecting the rear left radial conductor to the right front radial conductor.

3. In a heavy duty reversing switch, in combination, a base of insulating material having parallel side-walls, a

, pair of mechanically connected parallelly disposed conductors insulated from each other so pivotally mounted upon the base that angular movement of the conductors over a selected angle causes thefront conductor to sweep the front side-wall and the rear conductor to sweep the rear side-wall, three conductors, a first, second and third, disposed in spaced relation to each other in the front sidewall, and three similar conductors in the rear side-wall with corresponding conductors disposed oppositely to the first three conductors, the disposition of the three conductors in each of the side-walls being such that the front pivotal conductor, upon angular movement, selectively makes contact with the front first and third or the second front and third, or with neither of the first and second and the third, and at the same time the rear pivotal conductor selectively makes contact with the rear first and third, or the rear second and third, or with neither the rear first and second and the rear third, means for electrically connecting the left front, or first, conductor, with the right rear, or second, conductor, and means for electrically connecting the left rear, or first, conductor to the front right, or second, conductor, whereby pivotal movement of the pivotal conductors from one operative position to another operative position reverses the connection of the third front and rear conductors with respect to the left front and rear first conductors.

4. in a heavy duty reversing switch, in combination, a base having a front side-wall and a rear side-wall parallel to the front side-wall, a first relatively heavy low resistance metal strap, a second relatively heavy low resistance metal strap, a first connector, a second connector, a first bolt passing through the first connector the left end of the first strap, the base, the left end of the second strap, the bolt being insulated from the second strap, and a nut to firmly hold the parts together on the base, a second bolt pass-ing through the other end of the first strap and being insulated from this strap, through the base, the other end of the second strap, the second connector, and a nut on the bolt to firmly hold the straps in the side-walls in spaced parallel relation, an opening having a cylindrical side-wall disposed in the base to one side of the straps, a pair of sections of a cylinder disposed to match the cylindrical side-wall of the opening, a pair of side bars and coupling connections and bolts insulated from the side bars and connectors and sections pivotally holding the side bars in the opening, whereby the side bars may be made to move so that the front bar sweeps the front side-wall of the base and the rear bar sweeps the rear side-wall of the base, a front left terminal in the front side-wall, a left rear terminal opposite the left front terminal in the rear side-wall, a right front terminal in the front side-wall, and a right rear terminal, opposite the right front terminal, in the rear side-wall, the disposition of the terminals being such that the front side bar may selectively bridge the left front terminal and front strap or the right front terminal and the front strap, while at the same time the rear side bar may selectively bridge the left rear terminal and the rear strap, or the right rear terminal and the rear strap, a first jumper connection of relatively heavy low'resistance metal for connecting the left front terminal and the right rear termi- .nal and a second similar jumper connection, bowed upwardly and away from the first jumper connection so as not to cause a false circuit connection, connecting the left rear terminal to the right front terminal.

5. In a heavy duty reversing switch, in combination, a base of insulating material, a pair of relatively heavy straps of low resistanc bare conductive material disposed in parallel relation on the base, a pair of spaced low resistance terminals disposed above the first, or front, strap, a similar pair of terminals disposed above the second, or rear, strap, a pair of relatively heavy low re sistance bare contact bridging bars electrically insulated from each other but mechanically connected in parallel relation to each other mounted for movement on the base so that the front bar continuously engages the front strap but selectively engages one or the other front terminals while at the same time the rear bar continuously engages the rear strap but selectively engages the rear terminals, a low resistance jumper connection from the first front terminal to the second rear terminal, and a similar jumper connection from the first rear terminal to the second front terminal.

6. In a reversing switch, in combination, a base of insulating material, a pair of bare conductors disposed in parallel relation on the base, a pair of spaced terminals above the front conductor, a similar pair of terminals disposed above the other or rear conductor, a first bar movably mounted on the base to continuously engage the aeeesse front conductor and selectively engage the terminals above this conductor, "a second similar bar, movable in unison with the first, continuously engaging the second or rear conductor and selectively engaging the terminals above the rear conductor, connecting means between the left hand terminal above the front conductor and the right hand terminal above the rear conductor, and connecting means between the left hand terminal above the rear conductor and the right hand terminal above the front conductor.

References Cited in the file of this patent UNITED STATES PATENTS Anderson May 8, 1906 Lindae May 14, 1940 Dietrich Apr. 27, 1948 

1. IN A HEAVY DUTY REVERSING SWITCH, IN COMBINATION, A BASE OF INSULATING MATERIAL HAVING A FRONT SIDE-WALL AND A PARALLEL DISPOSED REAR SIDE-WALL, A FIRST GROUP OF THREE RELATIVELY HEAVY STRAP-LIKE METAL CONDUCTORS MOUNTED ON THE FRONT SIDE-WALL, TWO OF SAID CONDUCTORS BEING DISPOSED AT A SELECTED ANGLE WITH RESPECT TO EACH OTHER AND RADIALLY WITH RESPECT TO A PIVOT AXIS NORMAL TO THE SIDE-WALLS AND HAVING THEIR INNER ENDS SPACED FROM THE PIVOT AXIS, THE THIRD CONDUCTOR BEING DISPOSED TO ONE SIDE OF THE PIVOT AXIS AND ANGULARLY SPACED FROM SAID TWO CONDUCTORS, A SIMILAR SECOND GROUP OF THREE CONDUCTORS MOUNTED SIMILARLY ON THE REAR SIDE-WALL WITH CORRESPONDING CONDUCTORS OF THE TWO GROUPS BEING DISPOSED IN PARALLEL RELATION TO EACH OTHER, CONNECTORS CONNECTED TO THE THIRD CONDUCTOR OF EACH GROUP ACROSS WHICH A LOAD TO BE CONTROLLED MAY BE CONNECTED, A PAIR OF STRAP-LIKE RELATIVELY HEAVY METAL CONDUCTORS PIVOTALLY MOUNTED AT SAID PIVOT AXIS AND DISPOSED IN PARALLEL RELATION TO EACH OTHER WITH THE FRONT PIVOTAL CONDUCTOR BEING DISPOSED TO SWEEP THE FRONT SIDEWALL AND THE REAR PIVOTAL CONDUCTOR BEING DISPOSED TO SWEEP THE REAR SIDE-WALL, WHEREBY THE FRONT PIVOTAL CONDUCTOR MAY BE SELECTIVELY MOVED TO CONNECT EITHER THE FIRST RADIAL CONDUCTOR OF THE FRONT GROUP TO THE THIRD OF THE FRONT GROUP OR THE SECOND RADIAL CONDUCTOR OF THE FRONT GROUP TO THE THIRD OF THE FRONT GROUP, OR NEITHER THE FIRST NOR SECOND OF THE FRONT GROUP TO THE THIRD OF THE FRONT GROUP WHILE AT THE SAME TIME THE REAR PIVOTAL CONDUCTOR DURING PIVOTAL MOVEMENT SELECTIVELY MAKES CONTACT WITH CORRESPONDING CONDUCTORS OF THE REAR GROUP OF THREE CONDUCTORS, A FIRST JUMPER CONNECTION FROM THE LEFT FRONT RADIAL CONDUCTOR TO THE RIGHT REAR RADIAL CONDUCTOR, A SECOND JUMPER CONNECTION FROM THE LEFT REAR RADIAL CONDUCTOR TO THE FRONT RIGHT RADIAL CONDUCTOR, AND CONNECTOR MEANS WHEREBY A SUITABLE SOURCE OF ELECTRIC ENERGY MAY BE CONNECTED ACROSS SAID LEFT FRONT RADIAL CONDUCTOR AND REAR LEFT RADIAL CONDUCTOR, WHEREBY MOVEMENT OF SAID PIVOTAL CONDUCTORS FROM A SELECTED COUNTERCLOCKWISE POSITION TO A SELECTED CLOCKWISE POSITION WILL EFFECT REVERSAL OF THE CONNECTION OF THE LOAD TO THE SOURCE OF ELECTRIC ENERGY. 